The present invention relates to covers for openings, for example, in storage tanks. More particularly, the invention relates to cover systems for openings or hatches in vessels, for example, fuel storage tanks, such as the hatches used to monitor or gauge the amount and/or quality of material in the vessel.
Storage tanks, such as gasoline or other liquid fuel tanks, are often periodically monitored to determine the amount and/or quality of the liquid present. This monitoring is performed using gauging and/or sampling and/or temperature sensing equipment, such as that which is conventional and well known in the art. This gauging and/or sampling and/or temperature monitoring is done through a relatively small (smaller than a manhole) opening or access hatch in the vessel. The human doing the gauging and/or sampling opens the access hatch, performs the desired gauging and/or sampling, and then closes the access hatch.
Opening and closing the access hatch can be very difficult because the person performing these operations also is carrying the gauging and/or sampling equipment and/or samples. This is particularly difficult with storage tanks in cold environs and/or which are used to store corrosive materials. In addition, governmental regulations relating to emissions make it even more important to properly close the access hatch after gauging and/or sampling.
Therefore, it would be advantageous to have a hatch cover system which can be easily and effectively opened and closed.